Stilman White of the North Carolina Tar Heels drives for a shot attempt against Jon Smith of the Ohio Bobcats. (Andy Lyons, Getty Images)

ST. LOUIS — Awful all night, Harrison Barnes came through when North Carolina needed him most.

Barnes scored five of his 12 points in overtime and the top-seeded Tar Heels escaped a huge upset with a 73-65 victory over 13th-seeded Ohio on Friday night in the Midwest Regional semifinals.

Ohio, trying to become the first team seeded 13th or worse to make the regional finals since the NCAA tournament expanded in 1985, had a chance to convert a three-point play that would have given the Bobcats the lead with 25 seconds left in regulation. Walter Offutt missed from the line, however, and Ohio went 0 for 6 from the field in the first overtime of this year's tournament.

"One free throw away," Offutt said. "As a leader on this team, I take responsibility that I've got to hit that free throw. ... It just feels terrible to kind of let my team down in that sort of way."

Tyler Zeller finished with 20 points and a career-high 22 rebounds for North Carolina, which sorely missed injured point guard Kendall Marshall. The Tar Heels had three players with double-doubles for the first time in an NCAA tournament game: Reggie Bullock had 17 points and 10 boards, and John Henson had 14 points and 10 rebounds.

"It means a heck of a lot," coach Roy Williams said moments after his team escaped, "but we've got to play better than we did today."

The Jayhawks (30-6) advanced to play top-seeded North Carolina for a spot in the Final Four when Richard Howell's off-balanced heave at the buzzer came up well short.

Elijah Johnson added 11 points for the Jayhawks, including a layup off an inbound pass from Tyshawn Taylor with 13.5 seconds remaining that gave them a calming cushion.

N.C. State coach Mark Gottfried called a timeout to set up a play, but Scott Wood stepped out of bounds while fielding a cross-court pass with 5 seconds left. C.J. Leslie had 18 points for the Wolfpack (24-13), despite sitting much of the second half with four fouls.

North Carolina freshman point guard Stilman White — who plans on leaving school later this year to serve an L.D.S. mission made the first start of his college basketball career, finishing with six assists and no turnovers.